I've been using Helix Ultimate for many years and I'm very happy with it. I created a website with management functions using the Cassiopeia base template.
Now, however, I'd like to install the Helix Ultimate Mega Menu. So I'd also like to install Helix Ultimate and assign some menu items to this template, but within the Mega Menu structure. But I've never used Mega Menus; I've always disabled them, even from the Quickstart installations. I think it's a very simple thing to do, but honestly, I don't know how to do it.